On Target Counting by Sequential Snapshots of Binary Proximity Sensors

Counting and tracking multiple targets by binary proximity sensors (BPS) is known difficult because a BPS in “on” state cannot distinguish how many targets are presenting in its sensing range. Existing approaches investigated target counting by utilizing joint readings of a network of BPSs, called a snapshot [2,11]. A recent work [14] presented a snapshot-based target counting lower bound. But counting by individual snapshot has not fully utilized the information between the sequential readings of BPSs. This paper exploits the spatial and temporal dependency introduced by a sequence of snapshots to improve the counting bounds and resolution. In particular, a dynamic counting scheme which considers the dependency among the snapshots were developed. It leads to a dynamic lower bound and a dynamic upper bound respectively. Based on them, an improved precisely counting condition was presented. Simulations were conducted to verify the improved counting limits, which showed the improvements than the snapshot-based methods.